import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // TRY THIS: Try running your application with "flutter run". You'll see
        // the application has a blue toolbar. Then, without quitting the app,
        // try changing the seedColor in the colorScheme below to Colors.green
        // and then invoke "hot reload" (save your changes or press the "hot
        // reload" button in a Flutter-supported IDE, or press "r" if you used
        // the command line to start the app).
        //
        // Notice that the counter didn't reset back to zero; the application
        // state is not lost during the reload. To reset the state, use hot
        // restart instead.
        //
        // This works for code too, not just values: Most code changes can be
        // tested with just a hot reload.
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: '易信'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  int _selectedIndex = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  /// Tab 改变
  void onTabChanged(int value) {
    _selectedIndex = value;
    setState(() {});
  }


  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // TRY THIS: Try changing the color here to a specific color (to
        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
        // change color while the other colors stay the same.
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: const MyPageHeaderWeiXin(),
      ),
      bottomNavigationBar: BottomNavigationBar( // 底部导航
        items: const <BottomNavigationBarItem>[
          BottomNavigationBarItem(icon: Icon(Icons.chat_bubble,), label:"微信"),
          BottomNavigationBarItem(icon: Icon(Icons.supervisor_account,), label:"通讯录"),
          BottomNavigationBarItem(icon: Icon(Icons.explore), label:"发现"),
          BottomNavigationBarItem(icon: Icon(Icons.person), label:"我"),
        ],
        currentIndex: _selectedIndex,
        // 背景颜色
        backgroundColor: Colors.black,
        // 选中颜色
        selectedItemColor: Colors.green,
        unselectedItemColor: Colors.lightGreen,
        // 选中图标主题
        selectedIconTheme: const IconThemeData(
          // 图标颜色
          color: Colors.green,
          // 图标大小
          size: 32,
          // 图标透明度
          opacity: 1.0,
        ),
        // 未选中图标主题
        unselectedIconTheme: const IconThemeData(
          color: Colors.black,
          size: 24,
          opacity: 0.5,
        ),
        onTap: onTabChanged,
      ),

      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          //
          // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
          // action in the IDE, or press "p" in the console), to see the
          // wireframe for each widget.
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
            TextButton(
              child: const Text("open new route"),
              onPressed: () {
                //导航到新路由
                Navigator.push(
                  context,
                  MaterialPageRoute(builder: (context) {
                    return NewRoute();
                  }),
                );
              },
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

class MyPageHeaderWeiXin extends StatelessWidget {
  const MyPageHeaderWeiXin({super.key});


  @override
  Widget build(BuildContext context) {
    return const Flex(
      direction: Axis.horizontal, //弹性布局的方向, Row默认为水平方向，Column默认为垂直方向
      children: <Widget>[
        Expanded(flex: 7,
            child: Text("")),
        Expanded(flex: 7,
            child: Text("微信")),
        Expanded(flex: 1,
            child:Icon(
              Icons.search,
            )),
        Expanded(flex: 1,
            child:Icon(
              Icons.add_circle_outline,
            )),
      ],
    );

    // return const  Row(
    //   mainAxisAlignment: MainAxisAlignment.center,
    //   mainAxisSize:MainAxisSize.max,
    //   children: <Widget>[
    //     Text("微信"),
    //     Row(
    //       mainAxisAlignment: MainAxisAlignment.end,
    //       mainAxisSize:MainAxisSize.max,
    //       textDirection:TextDirection.ltr,
    //       children: <Widget>[
    //         Icon(
    //           Icons.search,
    //         ),
    //         Icon(Icons.add_circle_outline)
    //       ],
    //     )
    //   ],
    // );
  }
}

class NewRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("New route"),
      ),
      body: const Center(
        child: Text("This is new route"),
      ),
    );
  }
}
